Development of mechanical system for a small biped entertainment robot

SDR-4X II is the latest prototype model which is a small humanoid type robot. We reported the outline of the robot SDR-4X last year SDR-4X II is the improved model of SDR-4X. In this paper we discuss about mechanical system which is important and original for a small biped entertainment robot which will be used in home environment. One technology is the actuator technology which we originally developped named Intelligent Servo Actuator (ISA). We explain the specification and the important technical points. Another technology is the design of actuators alignment in the body which enables dynamic motion performance. Next technology is the sensor system which supports the high performance of the robot, especially the detection of outside objects, ability of stable walking motion and safe interaction with human. The robot is used in normal home environment, so we should strongly consider the falling-over of the robot. We propose the ideas against falling-over which makes the robot as safe as possible.